% VAR - variance of memory mapped underlying array
%
% Author: Arnaud Delorme, SCCN, INC, UCSD, Nov. 2008

% Copyright (C) 2008 Arnaud Delorme, SCCN, INC, UCSD
%
% This file is part of EEGLAB, see http://www.eeglab.org
% for the documentation and details.
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function sumval = var(obj,flag,dim)
    
    if nargin < 2
        flag = 0;
    end
    if nargin < 3
        dim = 1;
    end
    
    meanvalsq = mean(obj,dim).^2;
    
    sumval = 0;
    s1  = size(obj);
    ss.type = '()';
    ss.subs(1:length(s1)) = { ':' };
    for index = 1:s1(dim)
        ss.subs{dim} = index;
        tmpdata = subsref(obj, ss);
        sumval = sumval + tmpdata.*tmpdata - meanvalsq;
    end
    if isempty(flag) || flag == 0
         sumval = sumval/(size(obj,dim)-1);
    else sumval = sumval/size(obj,dim);
    end
